.app {
    font-family: sans-serif;
    border: 1px solid #eee;
    border-radius: 2px;
    padding: 20px 30px;
    margin-top: 1em;
    margin-bottom: 40px;
    user-select: none;
    overflow-x: auto;
}

.tab-button {
    padding: 6px 10px;
    border-top-left-radius: 3px;
    border-top-right-radius: 3px;
    border: 1px solid #ccc;
    cursor: pointer;
    background: #f0f0f0;
    margin-bottom: -1px;
    margin-right: -1px;
}

.tab-button:hover {
    background: #e0e0e0;
}

.tab-button.active {
    background: #e0e0e0;
}

.demo-tab {
    border: 1px solid #ccc;
    padding: 10px;
}